Effect

In battle

Strength inflicts damage and has no secondary effect.

Outside of battle

Generations I to III

Players can move round boulders around the field by walking into them whilst Strength is active. Many puzzles in the games require boulders to be moved around in a certain way with Strength. If the area is left, the boulders will resume their original positions and the puzzle needs to be solved again if the player wishes to go back through the area. However, the boulders will not reset after being dropped from one floor to the floor below, such as in the Ice Path and Blackthorn Gym.

Strength can be activated at any time.

Generation IV

Strength can now only be activated when there is a boulder in the vicinity.

Generation V

Boulders are now significantly bigger in size and are required to be pushed into holes and walked across, as opposed to pushed into corners and walked around. Once pushed into a hole, the boulders typically do not reset upon subsequent visits, and they do not need to be pushed again.

In other games

Strength sends the target flying to another tile in the room. The thrown Pokémon will bounce off of a single hostile Pokémon before landing as long as at least one is in range, causing both of them take 10 damage.

Trivia

If Secret Power is used in a building in Generation III, it will display the animation of Strength.

Although HM moves cannot be used outside of battle in Orre, Pokémon XD: Gale of Darkness has three locations housing puzzles similar to Strength puzzles in other regions:

The first two puzzle are located at the S.S. Libra and Cipher Key Lair, where several areas are blocked off by big wooden crates, which the player must push to either clear way, close a gap, or press a big switch in order to proceed or access an item. Similar to Strength boulders before Generation V, these crates will reset if the player leaves and re-enters the area.

The third puzzle can be found at Citadark Isle, where the player must push big metal blocks down small cliffs to stop flows of lava in order to progress and access certain items. These blocks will not reset once pushed down to their proper spots.

In the Generation IVcore series games, each time a Pokémon performs the animation for Strength in battle, its sprite will be translated right one pixel.

In Generation VII, Machamp becoming the signature user of Strength coincides with its new role as a Ride Pokémon, which replaces Strength's out-of-battle function that existed in previous generations.